Through-substrate via power gating and delivery bipolar transistor

Abstract

Embodiments herein describe a through-substrate via formed in a semiconductor substrate that includes a transistor. In one embodiment, the through via includes a BJT which includes different doped semiconductor layers that form a collector, a base, and an emitter. The through via can also include metal contacts to the collector, base, and emitter which enable the through to be coupled to a metal routing layer or a solder bump.

What is claimed is: 
     
       1. A semiconductor substrate, comprising:
 a through-substrate via (TSV) comprising:
 a sidewall insulator defining an outer boundary of the TSV, and 
 a bipolar junction transistor disposed within the sidewall insulator, the bipolar junction transistor comprising:
 a first semiconductor layer doped with a first-type of dopant, wherein the first semiconductor layer comprises a collector, 
 a second semiconductor layer doped with a second-type of dopant, wherein the second semiconductor layer comprises a base, and 
 a third semiconductor layer doped with the first-type of dopant, wherein the third semiconductor layer comprises an emitter, and wherein the first, second, and third semiconductor layers are arranged in the TSV to form one of: a PNP junction and an NPN junction, wherein the base is disposed between the collector and the emitter in the TSV, wherein a material of the collector forms an annular shape, wherein a base contact is disposed in a central opening of the annular shape, wherein the base contact comprises a conductive material that directly contacts the base in the second semiconductor layer. 
 
 
 
     
     
       2. The semiconductor substrate of  claim 1 , wherein the TSV extends from a top surface of the semiconductor substrate to a bottom surface of the semiconductor substrate opposite the top surface, wherein the base contact and the collector are closer to the top surface than the emitter and wherein the emitter is closer to the bottom surface than the base contact and the collector. 
     
     
       3. The semiconductor substrate of  claim 1 , further comprising:
 a metal routing layer comprising routing traces electrically coupling the bipolar junction transistor to electrical components disposed in the semiconductor substrate that are outside of the sidewall insulator. 
 
     
     
       4. An assembly, comprising:
 a through-substrate via (TSV) extending through a semiconductor substrate, the TSV comprising:
 a sidewall insulator, and 
 a bipolar transistor disposed within the sidewall insulator, the bipolar transistor comprising:
 a first semiconductor layer doped with a first-type of dopant, 
 wherein the first semiconductor layer comprises a collector, 
 a second semiconductor layer doped with a second-type of dopant, wherein the second semiconductor layer comprises a base, and 
 a third semiconductor layer doped with the first-type of dopant, wherein the third semiconductor layer comprises an emitter; 
 a first substrate; and 
 a solder connection coupling a first end of the TSV to the first substrate, wherein the base is disposed between the collector and the emitter in the TSV, wherein a material of the collector forms an annular shape, wherein a base contact is disposed in a central opening of the annular shape, and wherein the base contact comprises a conductive material that directly contacts the base in the second semiconductor layer. 
 
 
 
     
     
       5. The assembly of  claim 4 , a metal routing layer disposed on the semiconductor substrate, wherein a second end of the TSV opposite the first end is electrically coupled to at least one routing trace in the metal routing layer.